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FEC FUSIONE-HS-2 User Manual

Page 100

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Chapter 6: Fastening Instructions

Page 6-4

 

Two-Step Fastening

Two-step fastening will be used primarily for joints that have a requirement to synchronize

with another spindle during the final stage of the rundown or require joint conditioning. Ex-

amples: Connecting Rod, Main Bearing Cap, any multiple-spindle application.

1. Once SPEED CHANGE TORQUE is reached or FREERUN REVOLUTIONS expires, the sys-

tem will switch from FREERUN SPEED to SLOWDOWN SPEED and continue to fasten to

1ST TORQUE.

2. The system will fasten to the 1ST TORQUE value during the specified 1ST TIME. 1ST

TORQUE must be reached within the 1ST TIME limits or a reject will occur.

3. Upon reaching 1ST TORQUE, 1ST TIME ends and FINAL TIME begins. 1ST TORQUE is

the shift point to TORQUE SPEED and the synchronization point prior to commencing the

next step. (See 4.13 for Sync. info)

4. The system will fasten to STANDARD TORQUE using TORQUE SPEED during FINAL TIME.

STANDARD TORQUE must be reached within the FINAL TIME limits or a reject will occur.

FUNCTION

RECOMMENDATION / COMMENT

SPEED CHANGE TORQUE

10% of STANDARD TORQUE

THRESHOLD TORQUE

Start point of 1

st

torque rate monitoring (section 6.2)

1ST TORQUE

30% of STANDARD TORQUE

Used for RATE/TIME settings and TORQUE SPEED initiation.

Synchronization point for 2ND STEP

SNUG TORQUE

Angle Monitoring Start Point (section 6.2)

CROSSOVER TORQUE

Start point of 3

RD

torque rate monitoring (section 6.2)

STANDARD TORQUE

Engineered product fastening specification

1ST TIME HIGH/LOW LIMIT

Acceptance range to reach 1ST TORQUE setting

FINAL TIME HIGH/LOW LIMIT Acceptance range to go from 1ST TORQUE to STANDARD

TORQUE

FIG. 6-1-1b Torque Control Functions for Two-Step Fastening

Standard Torque

Threshold Torque

Speed Change Torque

1

st

Torque

Crossover Torque

1

st

Time

Final Time

Snug Torque

Torque

Angle/Time